Mm... don't think we really talked about either. Diffraction produces rainbows on things like CDs, but it's not important when talking about prisms. And transverse waves, such as light, don't have rarefactions. That's more dealing with sound and such.

In the example of a prism, yes but atleast one person has talked about something relating to the other without knowing (i haven't read the full argument).

i thought this whole thread was a troll until i started reading it....
This is why we can't have nice things.

Place water in a pan, place a mirror in the pan so its bent at 45 degrees, shine light through water onto mirror at it, light now refracts twice - once going in the water and then when it comes out giving you enough refraction to the light to have spread into the visible EM spectrum. (Exact same as that video) - although its not an actual rainbow cause you need to shine the light onto a solid surface, and image is not conventionally holographic 2 d rainbow curved projection.

You still have yet to explain why you just need water and a light (the sun) outside and you need [glass ,prism, mirror] as well on the inside and there still not the same thing, since you just wanna discuss this, feel free to teach me some science.

Same thing happens with a raindrop. Water refracts going in once, reflects off the back wall, then refracts again going out. It refracts twice going into a water prism - once going in and once going out. Any time you shine light through water and then onto a dry wall, it will refract twice - going in and going out. The mirror in water makes no difference, it doesn't increase the number of times light refracts. The only thing it does is create a path of light similar to a prism, with light rays refracting through two angled surfaces. The reflection off the mirror doesn't change the light at all, it's just reflecting.

You don't need a glass inside, you just need something to hold the water in a certain shape. You could, for example, create an ice prism (which has about the same refractive index as liquid water) and it would work just fine with no glass or mirrors involved. The only problem with water is getting the right shape, which means having some transparent container made of glass, plastic, whatever.

who knows

the mirror is reflecting the refracted light allowing the light to refract twice and as well light travelling through the glass in the mirror which slows down the dispersion too, i think it presents an inverted image too. Anyway its clear there's a difference between inside and out and I dont think water and light is enough for either one, you just dont see the [glass/mirror/prism/plasmasphere/dome structure] on the outside and will never acknowledge it actually exists even though actual science you love to agree with confirmed it.

Like I said, the light will always refract twice, whether there's a mirror or not. Light has to go in and out of water, doesn't it?

Would an ice be the same as water? If I show you an ice prism making a rainbow, would that convince you that water can make one too?

Light refracting twice through water isn't enough, imho it also needs a way to slow down the dispersion, - and isn't the light slightly refracted 4 x in my experiment 2x in the water and 2 x in the mirror with further dispersion in the glass on the mirror?

Athough i ve never seen an experiment with a 10,000 watt bulb, out of those atm...

What if outside the raindrop is actually refracting the light 4 x ?

2x from the sun

2x from the reflection of the light off the dome? And because the dome is curved - the rainbow is curved?

This post was edited by card_sultan on Jan 11 2017 05:57pm

losing brain cells from every word...